Ketosis

  • Definition:
    Ketosis is a metabolic condition characterized by elevated ketone bodies - acetoacetate, β-hydroxybutyrate, and acetone - in blood (>1 mmol/L; normal: <0.2 mmol/L) due to increased fat breakdown and incomplete oxidation in carbohydrate deficiency.

  • Causes:

    • Prolonged fasting / starvation

    • Uncontrolled diabetes mellitus (especially Type 1)

    • Low-carbohydrate, high-fat diets

    • Prolonged exercise

  • Biochemical Basis:

    • Occurs when acetyl-CoA from β-oxidation exceeds the capacity of the TCA cycle (due to low oxaloacetate).

    • Excess acetyl-CoA is converted into ketone bodies in the liver mitochondria.

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